83d4698cc9
In VACUUM FULL, an interrupt after the initial transaction has been recorded as committed can cause postmaster to restart with the following error message: PANIC: cannot abort transaction NNNN, it was already committed This problem has been reported many times. In lazy VACUUM, an interrupt after the table has been truncated by lazy_truncate_heap causes other backends' relcache to still point to the removed pages; this can cause future INSERT and UPDATE queries to error out with the following error message: could not read block XX of relation 1663/NNN/MMMM: read only 0 of 8192 bytes The window to this race condition is extremely narrow, but it has been seen in the wild involving a cancelled autovacuum process. The solution for both problems is to inhibit interrupts in both operations until after the respective transactions have been committed. It's not a complete solution, because the transaction could theoretically be aborted by some other error, but at least fixes the most common causes of both problems.
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Changes between all PostgreSQL releases are recorded in the file HISTORY. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.